The invention pertains to an actuating unit for an electromechanically actuatable disk brake for motor vehicles, the unit being mounted on a brake caliper. Two friction linings, each of which works together with one of the lateral surfaces of a brake disk, are mounted in the caliper with freedom to move within a limited range. An actuating element of the actuating unit brings one of the friction linings into engagement with the brake disk directly, whereas the other friction lining is brought into engagement with the brake disk indirectly through the action of the reaction force applied by the brake caliper. The actuating unit consists of an electric motor; a first reducing gear, which acts between the electric motor and the actuating element; and a second reducing gear, which acts between the electric motor and a part of the first reducing gear. The actuating unit also has an electronic controller, which serves to drive the electric motor.
An electromechanical actuating unit of this type is known from International Patent Application WO 00/61962. In the previously known actuating unit, the electronic controller is structurally separate from the actuating unit and is located apart from it.
The previously known actuating unit suffers in particular from the disadvantage that electrical lines with large cross sections are required to transmit the required electric power or current for all of the brake functions (service brake and parking braking functions). As a result, the distance between the actuating unit and the associated electronic controller is considered critical, especially when a brushless electric motor is used. The separate arrangement of the previously mentioned components also causes considerable problems with respect to packaging.
It is therefore the task of the present invention to propose an electromechanical actuating unit of the general type indicated above which is characterized by a significant reduction in the distance between the actuating unit and its associated electronic controller and by an optimized design with respect to packaging.